Safety key for locks with tumblers



April 28, 1936. o. c. RECHT ET AL 2,038,677

SAFETYYKEY FOR LOCKS WITH TUMBLERS Filed Aug. 51, 1934 2 Sheets-Sheet l g l f f er -H0M :Qg "hams. 22 1% L I April 28, 1936. O c E HT r AL 2,038,677

SAFETY KEY FOR LOCKS WITH TUMBLERS Filed Aug. 51, 1934 2 Sheets-Sheet 2 Patented Apr. '28, 1936 UNITED STATES 2,038,677 SAFETY KEY FOR LOOKS WITH TULIBLERS Oskar Camillo Recht, Stockdorf, near Munich, Germany, and Age Lcnberg-Holm, Hellerup, near Copenhagen, Denmark Application August 31, 1934, Serial No. 742,276 In Denmark October 2, 1933 9 Claims.

- This invention relates to safety keys for looks with tumblers, and the principal object of the invention is to provide a key which cannot be used by any unauthorized person.

A safety look as e. g. a Chubb or a Yale lock can usually be opened by anyone in possession of the proper key. It has therefore been proposed by several inventors to introduce keys with adjustable elements, which must be placed in certain relation to each other before the key can be inserted in the lock or can move the lock-bolts, in order to ensure security from an unauthorized opening of such locks. Adequate security has however not been attained with the known devices of this kind.

In the case of the present invention the key is fitted with adjustable elements having means for their mutual interlocking, and the key can only open the lock to which it belongs, when its elements have been placed beforehand in correct relation to each other and when the key is inserted in the correct position in the lock. The

arrangement of the interlocking means, however, is such that the adjustable elements will be freely movable and may occupy any position in relation to each other and to the main piece of the key as soon as this is withdrawn from the lock and as soon as the grip of the fingers on the handle of the key and their pressure on a wing or other suitable element is relased.

By this means only the person to whom the rule for the adjustment of the key-elements is known would be able to make use of the key for the opening of the lock in question. A forgotten, lost or copied key would therefore in itself not constitute the customary danger, as it could not be used by any unauthorized person, even if he knew to which lock it belongs.

By means of a sufficient number of adjustable key elements and a suitable number of possible adjustments of each of these elements, the possibility that a person who is not familiar with the adjustment rule might accidentally hit upon the correct adjustment, is reduced to such a minimum that the desired security is really obtained.

By a re-adjustment of the tumblers of the lock, the rule of adjustment for the elements of the safety-key may be changed at any time according to desire, so that if it is suspected that the adjustment rule hitherto employed has come to the knowledge of an unauthorized person, the security will be reestablished.

In order to make the rule of adjustment easier to remember, each element may be fitted on its surface with a cipher or letter corresponding to every possible position of such an element to its adjacent elements, from which ciphers or letters those in a certain column should form a definite number or word when the elements areadjusted in their right positions. r

This safety-key may be so arranged that when it is inserted in the lock and as longas the grip of the fingers on the key is retained, the interlocking of its elements in their correct positions I is secured, but not however after the grip has been released, even if the key remains in the lock. It may further be so arranged that the interlocking of the elements cannot be re-established before the key is withdrawn from the lock. .'Ihus no unauthorized person finding a key in the lock can discover the rule of adjustment simply by taking out the key, because. the key elements, during and afterthe withdrawal of the key, do

not remain interlocked and therefore easily become displaced, as is always the case when the 1:

key is not actually in use. The elements can moreover be constructed in such manner that their displacement in relation to each other and to the main piece of the key is furthered by adjust themselves on the insertion of the key,

and wherein:

Fig. 1 is a longitudinal section of the key as inserted in a lock..

Fig. 2 is a transverse section on line AB of Fig. 1.

Fig. 3 is a similar section on line I-K of Fig. 1.

Fig. 4 is a top end view of a stopping ring.

Fig. 5 is a section on line CD in Fig. 1.

Fig. 6 is an end view of an adjustable element of the key.

Fig.7 is a development of the face of the element in Fig. 6.

Fig. 8 is a front view of this element.

Fig. 9 is a section on line E-F GH of Fig. 1.

Fig. 10 is a top end View bottom of the key hole.

Fig. 11 is a top end view of another spring in the bottom of the key hole, and

cylindrical surof a spring inthe Fig. 12 is a view into the key hole when the.

key iswithdrawn.

Fig. 13 is an axial section of another embodiment of the invention showing a key inserted in a lock.

Referring in detail to the drawings the safetykey comprises a main piece I provided with a handle Consisting of two branches Ia and lb to which a yoke piece 2 is attached, having a hole for fixing the key to a key-ring or the like.

A cylindrical core 3 is movably located in a cen tral bore Ic in the main piece I and carries on 'the extremity which protrudes between the two branches of the handle a wing A which can be brought to rest against either of the two said branches. 7

A knob 5 on the core -3;can' slide along a I ringshaped surface of a recess Id in the outer end of the main piece I and from this can slide down a steep helical groove Ie in the inner cylindrical surface of the above mentioned cen-.

V tra-l bore Ic in the main piece.

A helicalspring 6 wound round the core 3 has it's one end attached to the knob 5- and its other to a knob 'I fixed in the mainpiece I-and tends at the-same time to turn thecore sand to pull it downwards in such away that the knob 5 will slide. along the above mentioned ring-shaped. .surface' and further into the helical: groove, thereby bringing the core as far through the main piece as is allowed by thewing 4 coming to rest against the one branch of the handle; this position is shown in full lines, Figs. 1 and 2 of the drawings, and is termed the"position of rest." 1

An axial pressure against a head 8 on the free extremity of the core3, followed by a pressure of the fingers against one side of the wing 4,

'will bring the core with its winginto the position shown by dotted lines on Fig: 1, which position corresponds to the state of the key before its insertion in the lock and is termed the interlocking position. The core will remain in this position as long as the pressure of the fingers rests on the wing 4 and thereby'counter- 7 911. in, this stopper, which prevents the knob 5 on ,the core from moving further out of the main' piece than corresponds to the resting 'of th knob against the ring-shaped surface. I

On the inner side of .this stopper 9 a: crevice 91) allows the knob 5 to slide a'certain distance along the ring-shaped surface after-having left the helical groove Ie, during' the motion o-f-the core 3 from its position of rest to its interlocking 1 position. O n' the other hand, this crevice 19b ensures that the knob 5 slidesfrom the ringshaped surface down into the groove Ie, during the motion of the core 3 from its interlocking position back into' its position of rest, when the pressure on the wing 4 has been released.

The free extremity of the core 3, carries a number of adjustable elements in the'form of rings III'which' are free to slide and turn in re has three rings I'Il, but-the number of rings may begreater or smaller.

actuating means. such as for instance one or The cylindrical surfaces j of these rings It are each provided with'tumbler' more cams II and/or grooves I2. The end surfaces of the rings ii! are provided with means for mutually interlocking the rings in a certain number of predetermined positions, such as cogs iila. as shown on Figs. 6-8; the end of the outermost ring Ii! facing the head 8 being however smooth. The end surface of the main piece I facing the innermost ring Ill is furnished with cogs or other interlocking means corresponding to those of the rings. These means allow for a certain number of adjustments of the rings in relation to each other and to the main piece, (in the form shown on thedrawings there are eight different adjustments of each element) and at the same time lock the adjustment when the rings are pressed against each other and against the main piece by means. of the head. 8 at the extremity of the core 3. With eight dif ferent adjustments of' each ring in relation to the main piece and to the adjacent rings and 7 with; three rings in all, there will be 512 different chmbinations possible; with four rings there will be 4096, and so on.

The part I f of the main piece I facing the rings In is formed like a cylinder, having the same. diameter as the rings. This'part I f may be furnished with one or more belts of cams II and grooves I2 corresponding to those on the rings, inthis 'case one belt Ig. Following this belt there is another belt provided with cogs Ih,'behind which a collar' Us on the main piece limits the depth to which the key can be inserted in the lock.

The length of the core Sis such that the head 8 will keep the rings It pressed against each other and against the extremity of the 'main piece, if the coreis brought into its interlocking position mentioned above, i. e. with the wing resting against one ofthe branches of the handle, the right one on the drawings. Thus, if the rings II) have been adjusted in their right positions in relation to each other and to the 'main piece, the core 3 will keep them'interlocked inthis position, as'long as the core itself is kept in'its interlocking position.

When the key is not inuse, the core will be in its position of rest into which it automatically moves as soon as the grip of the fingers, on the handle of the key releases the pressure on the wing 4. The rings I ll willthen be free to move along and around the core 3. and they will shift their position under the influence of spontaneous external forces. Every time the keyis to be used, the elements will therefore have to be'adjusted afresh.

The corresponding lock in the form shown on the drawings is furnished with a cylindrical centre piece I3 the turning of which by means of the inserted key will result in the displacement of the bolt as usual. .This centre piece turns inside a cylinder. I l which is fixed to the. main part of the lock I5'which'again is mounted on the inner side of the door in such manner that'the cylinder i l fits into a hole in the door-frame and pro trucles through the hole almost to the outer side of the door-frame, where the hole is covered by an escutcheon. 25. The centre piece I3 is secured by appropriate means against removal from outside, even if the escutcheon has been taken 011.

The centre piece I3 is furnished with a cylindrical bore corresponding to the external diameter of the rings In which bore guides the key on.

its insertion .in the lock. Thecylindrical surface of the boreis furnished with a number of slots of rectangularcross-section. the number of slots to correspond with the number of adjustments of .the rings in relation to the main piece of the key,

e. g. in the form shown on the drawings there are eight slots. The cross-section of the slots corresponds with the cross-section of the cams on the rings and on the main piece of the key, also with the cross-section of the cogs on the cylindrical part of the main piece. The diameter of the bore near the bottom corresponds to the bottom of the slots, thus providing the necessary play for the cutting of the slots. In the bottom of the bore there is a hole for a screw 24.

Corresponding to the cams and/or grooves of the main piece and rings of the key,.the centre piece I3 of the lock is furnished with belts of radially movable tumblers [6, the number of tumblers in each, to be the same as the number of slots in the centre piece, as shown in Fig. 9. .The tumblers slide in holes in the centre piece l3 and may e. g. be furnished with heads to prevent them from being pressed further in than,

will leave a cylindrical passage between their extremities, with a radius corresponding to the distance from the axis of the core 3 of the key to the bottom of the grooves in the rings l0. Pistons l1 which slide in radial holes in the cylinder l4 press'against these heads under the influence of helical springs I8. When the door is locked the position of the centre piece l3 in relation to the cylinder I4 will be such that each tumbler l6 will be opposite a piston H. The springs l8 are kept in place by a tube !9 encasing the cylinder I4 and secured to this by a couple of screws. By an axial displacement of the tube l9 along the cylinder [4 the holes containing the helical springs, pistons and tumblers are uncovered, so that these elements can be replaced by others or exchanged.

The length of the tumblers I6 is adjusted in such manner that the points of contact between the tumblers and the pistons will correspond with the cylindrical surface of the centre piece l3 when the key, after having had its elements adjusted in the right way, is inserted in the lock in its right position. In this case the surface formed by the cylindrical part If of the main piece I of the key and of the rings I0 and also of the cams and grooves will press against the extremities of the tumblers, thereby moving them the necessary distance outwards from their position of rest. As long as the key is not inserted in the lock a certain number of the pistons I! will protrude with their extremities into the holes in the centre piece l3, and thereby prevent the turning of this piece and accordingly also prevent the opening of the look; if the adjusted key is inserted to the right depth the above mentioned locking of the centre piece l3 ceases.

By the interchanging of some sets of pistons l1 and corresponding tumblers IS with other sets, the adjustment of the key elements for the opening of the lock may be altered, e. g. if an unauthorized person has found out the rule of adjustment hitherto used.

The number of cams and grooves (in each belt of the key), as well as their mutual arrangement, being variable, an adequate number of variations is possible in order to avoid two looks with their keys becoming identical; the number of belts may also be varied.

When the grip of the fingers which keeps the wing 4 on the end of the core 3 pressed against the branch on the handle of the inserted key is released, the core will turn and slide down into its position of rest, thereby penetrating the bore in the centre piece'ofthe lock to a greater depth, on account of which this bore itself must have a corresponding depth. A cup-shaped spring 22 with fingers, one for each slot in the centre piece, prevents the rings ID from sliding further into the bore, when the core 3 with its head 8 slides further downwards as above described. A second spring 2| with fingers 2Ia resting against a cylindrical part 8a of the hand 8 when this head hasprotruded to its greatest depth in the bore, will prevent the re-turning of the core 3 and consequent movement into its interlocking position, as the cylindrical surface 8a of the head is formed like a ratchet wheel.

Both springs 2i and 22 are fixed in the bottom of the bore by means of a screw 24 with a Washer 23; the fingers of the springs protrude intothe ends of the slots, thus preventing the turning of the springs.

On the Withdrawal of the key from the lock, the friction between the extremities of the tumblers l6 and the surface of the rings I0 prevents these rings from sliding outwards with the key until the head 8 reaches the rings l0 and starts to press them out; this means that the rings ID are removed from the end of the main piece of the key. If the slots in the centre piece of the lock are made to follow helical lines of great pitch and if the cams and grooves of the rings, etc. are formed. accordingly and. also the position of adjustment of the elements to each other corresponds to the helical slots, the rings will turn around the core and'shift their positions in relation to the main piece of the key on its withdrawal from the lock, the release of the grip of the fingers having previously allowed the core with its head 8 to turn and slide into its position of rest. On the insertion of the adjusted key in the lock with helical slots, the entire key will of course have to be turned to a depth corresponding to the depth to which the foremost ring penetrates the bore.

In order to obtain a further security against an unauthorized use of the key the lock may according to the invention be so constructed that even if the key has been left correctly adjusted in the lock this cannot be opened as soon as the grip of the fingers on the wing 4 is released. This is obtained by an additional set of tumblers 25 for cooperation with the head 8 of the core 3. The tumblers .25 are placedin the centre piece l3 in alignment with the head 8 when this latter is in its lower or released position. The tumblers 25 are pressed inward by springs 21 through the medium of pistons 26 sliding in radial holes in the cylinder I 4. Theouter ends of the holes are closed by a cylindrical cover 28 keeping the springs 21 in place. The lengths of the tumblers 25 and the heads are so adjusted that, when the core 3 is in its upper position, the tumblers protrude into the key holeand the top of the heads are in alignment with the outer surface of the centre piece 13 thus allowing this centre piece to be turned by means of a correctly adjusted and interlocked key. As soon, however, as the wing 4 is released the core 3 will move downward, and its head 8 will force the tumblers 25 outward against the action of the springs 21. The heads of the tumblers consequently will reach into the cylinder 14, as shown in Fig. 1, and it is impossible to turn the centre piece I 3 in relation to the cylinder 14 even if all the rings 10 are correctly adjusted.-

An unauthorized person finding a correctly adjusted key inserted in the lock will consequently be unable to use the key and to openthe. lock.

Before the lock be opened it is necessary 7 that the key iswithdrawn from the lock, adjusted anew and again inserted in the lock, and the opening must be effected before the wing 4 is released.

Fig; 12'shows the key-hole before the insertion of the key. As a great number of tumblers will In this embodiment the core 3 is hollow being provided :with an axial bore extending through theheadB. 'In the bottom ofthe key-hole in the lockfisfixeda stem which extends axially in the key-hole and which passes into the bore in the 'corewhen the key'is inserted in the lock.

' The stem as is provided with longitudinal grooves sliding in'the grooves 3!.

3| in. its cylindrical surface and in an extension '32 of thebore within the head 8 there is'located a spring '33 which has a number of lugs or the like for cooperation with the grooves 3|. Instead of a single spring 33 with lugs a number .of shorter springsmay be used the ends of which cooperate with the grooves 3|. For preventing the rings ill from moving too far into the key-hole a ring 34 is located in theinner wall of the center piece I .3. r The head 8, which in this embodiment has a no outer ratchet teeth but has an even outer surface, may when the key is inserted in the key-hole pass through the ring 34, but the rings .III will be stopped by this ring 34, or their diametersi are too large for allowingthem to pass. The hollow core in passing over the stem. 30 and the; lugsor ends of the springs 33 are hereby The springs are so fixed in the head that they can slip from one groove 3| to another when the core is turned in one direction but prevent rotation in the other direction like ratchet pawls.

In this embodiment further the cover for the piston holes in the cylinder I4 consist of a'number, of rings '29 one for each belt'of pistons each ring 29 is provided With a hole which by turning the'ring aboutithe cylinder l4 may successively uncover the holes of the corresponding belt of pistons.

With locks of for example the Chubb system,

. the principle of the present invention could be introducedby providing the tumblers of such looks with openings corresponding to the adjust? ment of the cams-on the rings to each other. If one of the cams is not adjusted in the right position in relation to the main. piece of the key, the

corresponding tumbler will either be raised too much or too little, in neither .case' can the lock be opened. 7 v a 7 Having thus described our invention we claim: 51. A safety key comprising a 'main piece, a handle, fixed thereto, a core axially penerating the-said main piece and having a free portion protruding opposite the handle, and a number of 'ringshaped' adjustable elements arranged slidably on and 'turntab'learound the said free portion of the core, the adjustable elements being provided with tumbler actuating meanson their outer surfaces and with means for interlocking the elements ina, certain number of pre-arranged positionson-their end surfaces facing each other.

1 2A safety keyc'omprising a main piece, a

handle fixedithereto, a core axially penetrating,

the said main piece and having a free portion protruding opposite the handle, and a number of ringshaped adjustable elements arranged slidably on and turnable around the said free portion of the core, the adjustable elementsbeing provided with tumbler actuating means on their their end surringshaped adjustable elements arranged slidably on and turnable around the said freeportion of the core, theadjustable elements being provided with tumbler actuating meanson their outer surfaces and with means for interlocking the elements in'a certain number of pre-arrange'd positions ontheir end surfaces facing each other,

ments.

'20 and means for fixing the interlocking of the ele} 4. A safety key comprising a main'piece, a Y

handle fixed thereto, a cylindrical core axially displaceable in a bore in said main piece andpro truding from the bore to both sides, a number ofadjustable elements with tumbler actuating 7 means and interlocking means arranged around the said core on the end opposite the handleyand a head on said end of the core for pressing'the said elements against each other and against the main piece.

5. A safety key consisting of a main piece, a

handle fixed to one end of said main piece, an

axial bore in said main piece, a helical groove in the inner surface of said bore, a cylindrical core freely movable in said bore, a wing on the end of said core protruding into the handle; a number of adjustable ringshaped elements having tumbler actuating means and interlocking the handle, a head on the end of said'core op-' posite the handle, a knob on the core located in the said helical groove and a spring attached to the core and the main piece. l

6. A safety key consisting of a main piece, a.

40 means on the end of the core protruding opposite handle fixed to oneend of said main piece, an

axial bore in said main piece, a helical groove in the inner surface of said bore, a cylindrical core freely movable in said bore, a wing on the end of said core protruding into the handle, a'number of adjustable ringshaped elements having tumbler, actuating means and interlocking means on the end of the core pro-truding opposite the handle,'a head on the end of said core opposite the handle, a cylindrical, surface of said head provided with ratchet teeth for cooperation with fingers on 'a spring in the bottom of the key hole' in a look, a knob on the core located in the said helical groove and a springinterposedbetween the core and the said main piece.

'7. A safety'keycons'isting of a main piece, a

handle fixed to one 'end of said main piece, an

axial bore in said main piece, a helical groove 7 in the inner surfaceof said bore, a cylindrical core freely movable in said bore, a wing on the endof said core protruding'into the handle, a

number of adjustable ringshaped elements having tumbler actuating means and interlocking .means arranged side by side on theendof the core protruding opposite the handle, a head on the end of said core opposite the handle, acylindrical surface of said head provided. with ratchet teeth for cooperation with fingers on'a spring in the bottom of the key hole-in a lock,

a knob on the core located in the said helical groove, a spring fixed with one end to the core and with the other end to the main piece, a cylindrical belt on the main piece adjacent the adjustable elements said belt having tumbler actuating means on the cylindrical surface and interlocking means on the end surface, and a belt of cogs onthe main piece for cooperation with cogs on the center piece of a lock.

8. A safety key consisting of a main piece, a handle fixed to one end of said main piece, an axial bore in said main piece, a helical groove in the inner surface of said bore, a cylindrical core freely movable in said bore, a wing on the end of said core protruding into the handle, a number of adjustable ringshaped elements having tumbler actuating means on their cylindrical surfaces and interlocking means on their end surfaces arranged on the end of the core protruding opposite the handle, a head on the end of said core opposite the handle, a cylindrical surface of said head provided with ratchet teeth for cooperation with fingers on a cupshaped spring in the bottom of the key hole in a lock, a knob on the core located in the said helical groove, a spring urging the core in a direction opposite the handle, a cylindrical belt on the main piece adjacent the adjustable elements said belt having tumbler actuating means on the cylindrical surface and interlocking means on the end surface, a belt of cogs on the main piece for cooperation with cogs on the center piece of a lock and a collar on the main piece for limiting the depth to which the key can be inserted in a lock.

9. A safety key consisting of a main piece, a handle fixed to one end of said main piece, an axial bore in said main piece, a helical groove in the inner surface of said bore, a cylindrical hollow core freely movable in said bore, a wing on the end of said core protruding into the handle, a number of adjustable ringshaped elements having tumbler actuating means and interlocking means slidably arranged on the core, a head on the end of said core opposite the handle, springs in the cavity of said head acting as resilient ratchet teeth for cooperation with a grooved stem in the bottom of the key hole in a look, a knob on the core located in the said heli-- cal groove and a spring interposed between the core and the main piece.

OSKAR CAMILLO RECHT. AGE LfiNBERG-HOLM. 

